Metro dark fiber provider, BIG Fiber has announced the successful closing of a $250 million debt facility to help fund the growth of its vast digital infrastructure network around the US. The deal includes a $100 million accordion feature, raising total borrowing capacity to $350 million to fuel the AI computing boom.
Stonepeak Credit and La Caisse, a large Canadian institutional fund, led the round. Previous supporters, Columbia Capital and SDC Capital Partners, also continued supporting the company in the new credit establishment.
Before its dramatic corporate rebranding in May 2025, BIG Fiber was known as Bandwidth IG. BIG Fiber is focused on the buildout and ownership of all 100% underground, high-strand, metro dark fiber corridors. This dedicated capacity is what hyperscale cloud platforms, data centers and large enterprises need to run their growth in the face of record-setting artificial intelligence workloads.
Accelerating Cross-Country Infrastructure Builds
Much of the new capital will fund large infrastructure projects already in progress in BIG Fiber’s core regional markets. Up to 70% of proceeds will fund a multi-market buildout in Greater Atlanta, one of North America’s fastest-growing data center markets. This, in particular, would expand the regional network in excess of 205 route miles and 165,000 fiber miles.
Source: BIG Fiber
These funds will expand the infrastructure provider’s existing metro networks in the San Francisco Bay Area and Greater Portland, Oregon. After construction completion, BIG Fiber anticipates Atlanta and San Francisco network capacity will reach approximately 850 route miles and over 3 million fiber miles. The company has projected early 2027 for phased Ready for Service (RFS) deployments.
More News: The Path Raises $14.3M in Mental Health Seed Round
Meeting the Data Demands of the AI Era
The financial boost arrives at the perfect crossroads for network architecture designers. With growing AI capabilities and GPU farms, migrating data between minefields is now a key focus of the contemporary ICT industry. As hyperscalers relocate to avoid power grid limitations, high-strand dark fiber pathways are now integral to the larger technology stack. Data center operators are installing dedicated underground lines through BIG Fiber, creating direct local connections across campus facilities for constant data synchronicity.
Scaling Sustainable Infrastructure
The closing of this $250 million debt facility comes immediately after some other financial and operational achievements of this company. Building on 2024 momentum, the company achieved the first-ever green loan in this sector, committing to sustainable digital infrastructure. With new equity and refinancing, BIG Fiber can enter long-term agreements with data providers, securing recurring revenues and future compute capacity infrastructure.
